1/30/07 Blood Chapter 17

1/30/07 Cardiovascular system  Blood is a component of  Function ♦Supply O 2 to all cells & remove wastes ♦Transport hormones & other chemicals (e.g. ions) ♦Immune response  Composed of ♦The Heart ♦Blood vessels ♦BLOOD

1/30/07 Characteristics of Blood  Blood = fluid connective tissue  Composed of a variety of cells and their extracellular matrix 37-54%  Formed elements ♦Red Blood Cells ♦White Blood Cells ♦Platelets 46-63%  Liquid medium =  Plasma

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Plasma  Contains mostly water (92%)  Electrolytes and proteins (7%)  “Free-floating stuff”  Proteins ♦Always remain in the plasma – give viscous consistency  3 main plasma proteins ♦Albumin ♦Globulins ♦Fibrinogen

1/30/07 Plasma  Albumins ♦Help in maintaining osmotic pressure of blood ♦Transport thyroid hormones, fatty acids, etc.  Globulins ♦Immunoglobulins/antibodies for defense ♦Transport ions & hormones  Fibrinogen ♦Impt. in blood clotting  Blood tests: Plasma vs. Serum  Serum = plasma without fibrinogen ♦Thus the clotting factors are removed ♦but also removes Ca 2+ ions

1/30/07 Formed Elements Red Blood Cells = Erythrocytes (RBCs)  Function of RBC’s ♦Transports O 2 from tissue to lungs ♦Transports CO 2 from cells/tissue to lungs  Structure ♦Saucer-shaped cell = biconcave disk  Special features ♦No nucleus ♦No mitochondrion (no mitochondria)  Lack of these organelles is advantageous to function ♦No nucleus = no cell division = less energy spent & more space for O 2 ♦Cell can assume biconcave shape – this allows for the stacking of cells

1/30/07 Formed Elements: RBC’s  Importance of Shape to function (review in text)  No mitochondria ♦O 2 necessary for ATP production ♦If present, the O 2 will be consumed ♦Also gives more space in the cell Fig. 17-2

1/30/07 Fig. 17-3

1/30/07 Molecular content of RBC’s  Stocked with Hemoglobin (Hb) ♦Protein ♦Makes up 95% of all intracellular proteins ♦There are approx. 280 million molecules of Hb in each RBC ♦Normal range in grams per mL whole blood = g/dl ?  Hb = protein with 4 pieces (subunits)  4 polypeptide chains = Globins ♦α-globin & β-globin Fig. 17-3

1/30/07 Molecular content of RBC’s  Stocked with Hemoglobin (Hb)  4 polypeptide chains = Globins ♦α-globin & β-globin  With each globin there is a heme group ♦Special chemical compound containing Fe 2+ ♦Fe 2+ of globin binds to O 2  Blood leaving lungs is rich in O 2 ♦Fe- O 2 = oxyhemoglobin – bright red in color  Blood going to lungs containing CO 2 ♦= carbaminohemoglobin – dark red in color Fig. 17-3

1/30/07 Molecular content of RBC’s  RBC’s contain a special enzyme ♦Carbonic Anhydrase  Helps in CO 2 transport in the blood – (later) Fig. 17-3

1/30/07 Formed Elements: White Blood Cells  White Blood Cells = Leukocytes ♦Approx. 0.1% of blood total  Come in many shapes and forms  Granular (3 types) ♦Neutrophils ♦Eosinophils ♦Basophils  Agranular (2 types) ♦Lymphocytes ♦Monocytes  Common Features ♦Prominent Nucleus ♦Large size (compared to RBC’s) ♦No Hemoglobin Fig. 17-1

1/30/07 Formed Elements: White Blood Cells  Handout = specific targets of each type of WBC’s  Functions:  Clean Up & Defense ♦Detect pathogen invasions, provide protection ♦Remove dead cells and debris  “Guarding the Body” ♦“patrol the area” – travel along the edge of blood vessels  IF pathogen(s) have entered the body tissue & local defense has begun, chemicals are released  WBC’s are attracted to these chemicals & squeeze through endothelial cells to exit the blood vessel  They then find their way to the damaged tissue – this type of sensing and movement = chemotaxis

1/30/07 Formed Elements: Platelets  Platelets = Thrombocytes  Packages of cytoplasm  Function = clotting ♦Repair of slightly damaged blood vessels Fig. 17-2

1/30/07 Blood – day 2 Chapter 17

1/30/07 Formed Elements: Production  RBCs, WBCs, & Platelets are synthesized in the body  Production & recycling  Production of blood cells = Hemopoiesis  All blood cells originate from Hemocytoblast cells

1/30/07 Red Blood Cell Production  Location ♦Red bone marrow (myeloid tissue) of epiphysis of vertebrae, sternum, ribs, skull, scapulae, pelvis, proximal limb bones  Process – Fig  Hemocytoblast → becomes RBC  Process = Erythropoeisis  Requires a hormone = erythropoetin (peptide) ♦Stimulated by renal erythropoetic factor from the kidneys ♦Recall/review Fig. 16-7b

1/30/07 Red Blood Cell Production  Erythropoeisis  Erythropoetein (E.P.O.)  Simple version  Hemocytoblast loses nucleus

1/30/07 ro Fig. 17-2

1/30/07 Fig. 17-2